Growth of fungi on an inorganic medium

Abstract

A species of Cephalosporium and another of Fusarium were grown for 5 years on a medium devoid of any known, complex, organic carbon source. The organisms were grown on a solid as well as in a liquid medium and the growth rates under various conditions, based on increase in spore number and dry weight, were recorded. At initial stages of growth, there was a linear relationship between the rate of growth and CO2 gas and (or) HCO3− supplied. Direct evidence for assimilation of C14 from C14O2 was demonstrated through combustion analyses. Nitrogen supplied as either NH4Cl or KNO3 supported growth and C14O2 fixation. Although grown as heterotrophs, both species of fungi retained their ability to grow autotrophically or mixotrophically. Laboratory air, purged through sulfuric acid to eliminate trace organic contaminants from the air, supported growth of the Cephalosporium sp.